This invention relates generally to mechanical valves, and in particular to fluidic valves used for microfluidic applications such as biological assaying.
There is a growing demand for biological fluid processing systems that has generated a need for small fluidic valves. One class of biological fluid processing systems consists of disposable systems that are for single use. Many small fluidic valves are under investigation and a few have been distributed commercially. Most of these existing small fluidic valves couple a flexible diaphragm to a thermopneumatic, piezoelectric, electrostatic, electromagnetic, bimetallic, or other type of actuator. They generally suffer from complicated design and are generally too expensive to build. Fabrication of many existing small fluidic valves involves bulk processes (e.g., bulk etching of silicon) and surface processes (e.g., thin film process). Disparate materials (e.g., thin film resistive heaters in thermopneumatic valves, piezo material in piezoelectric valves, TiNi alloy in shape memory alloy valves, etc.) are often used in addition to a substrate material (e.g., Si). Not only is the fabrication process of such small fluidic valves complicated, but the integration into complex, microfluidic devices has also proven to be non-trivial. These types of small fluidic valves have generally found to be undesirable for used in single-use bio-microfluidic devices.
What is needed is a very low cost, highly reliable, microfluidic valve for disposable, single use bio-microfluidic devices.